RAM 1500 Van V8-5.2L CNG VIN T (1999)
Vacuum Check Valve HVAC: Testing and Inspection
VACUUM CHECK VALVE
Testing
1. Remove the vacuum check valve. The valve is located in the vacuum supply tube (black) within the vacuum harness on the left end of the
distribution duct under the instrument panel in the passenger compartment. The vacuum check valve must be removed in order to perform the
following tests. See Vacuum Check Valve Removal and Installation.
See: Service and Repair
2. Connect the test set vacuum supply hose to the heater-A/C control side of the valve. When connected to this side of the check valve, no vacuum
should pass and the test set gauge should return to the 27 kPa (8 in. Hg.) setting. If OK, go to step Step 3. If not OK, replace the faulty valve.
3. Connect the test set vacuum supply hose to the engine vacuum side of the valve. When connected to this side of the check valve, vacuum should
flow through the valve without restriction. If not OK, replace the faulty valve.
